"Would you tolerate" is kind of interesting phrasing.

It feels like there's no "one-size-fits-all" ideal level of intervention in a dysfunctional/repressive government. Sometimes if you just leave them alone, they "inevitably" liberalize, reaping the benefits. Sometimes if you just leave them alone they calcify, form coalitions, and actively interfere in Western democracies. Sometimes if you intervene a little, you can help support the people oust their rulers. Sometimes if you intervene a little, you just harm innocent civilians, and entrench the power of the regime. And so on and so forth for every possible level of intervention.

Sure, some of it is going to inherently depend on the actual level of the power disparity, on any counteracting support the regime is getting from your adversaries, on the particular details of your intentions and your intervention, on the timing, etc. But sometimes it really feels like nobody knows what they're doing with foreign policy, and sometimes you get lucky and the country where you literally nuke two major cities just sort of shrugs, shakes your hand, and becomes one of your closest allies with a great deal of goodwill between citizens, and on the other hand sometimes you put boots on the ground an funnel enormous sums of money and (at least hypothetically) try to maintain positive relationships with the locals in a huge nation-building project and after decades you end up with...nothing.

So, to go back to what you said, sometimes it feels like tolerating the fascist country in your backyard might be the best way to turn it into a non-fascist country. And, on the other hand, sometimes it might be the worst way. These things seem difficult.